The Dark Matter Theory: The Parameter Definition
by Stephen Tannhauser
Summary: Would-be actress Penny discovers her new neighbours Sheldon and Leonard have all sorts of wonderful geeky interests . . . and one very dark secret that will change her life forever.
1. Chapter 1

THE DARK MATTER THEORY: THE PARAMETER DEFINITION

By Stephen Tannhauser

 **Description:** Would-be actress Penny discovers her new neighbours Sheldon and Leonard have all sorts of wonderful geeky interests . . . and one very dark secret that will change her life forever.

 **Notes:** To any who may have found this story by following my other works, I want to reassure everyone that I have _not_ abandoned _The Metahuman Transfiguration_ ; I simply found myself struck by this idea so compulsively that I had to get it down before I could go on. Rest assured that I will continue both tales.

 **Disclaimer:** The author does not own THE BIG BANG THEORY or any of the characters. Much of the dialogue in this story is adapted from the screenplay for the Pilot Episode, written by Chuck Lorre and Bill Prady.

\- 1 -

PASADENA, CALIFORNIA—SEPTEMBER 24, 2007

"So if a photon is directed through a plane with two slits in it," said Sheldon as they moved down the featureless, turquoise-walled corridor towards a particular door, "and either slit is observed it will not go through both slits. If it's unobserved it will, however, if it's observed after it's left the plane but before it hits its target, it will not have gone through both slits."

Only half-listening, Leonard checked the door; there was no nameplate or sign on it, but he'd kept careful count of the doors they passed as per the directions in his hand. "Agreed," he said, turning the knob and opening it. "What's your point?" The answer was a touch sharper than it might normally have been, but his stomach was jumping in knots. It was always the part just beforehand that was most nerve-wracking.

If Sheldon felt any of the same nervousness, he didn't show it; he only looked blank. "There's no _point_. I just think it's a good idea for a T-shirt." He followed Leonard into the room, where the same bland turquoise walls surrounded an empty waiting area and a desk occupied by a single bored-looking receptionist scowling at a folded newspaper. Leonard glanced back at Sheldon, who closed the door and, with a carefully concealed and quiet movement of his hand, locked it.

They went to the desk together. The receptionist, a black woman who looked to be in her late thirties, didn't move or acknowledge their presence. Leonard cleared his throat. "Excuse me?"

"Hang on," said the receptionist flatly, not taking her eyes from what Leonard could now see was a crossword puzzle.

Leonard glanced at Sheldon. It was possible this was a gambit to buy time or put them off their guard, or it could just be a lazy employee, but either way, he wasn't in the mood to play games. He saw Sheldon's agreement in his calm flicker of a return nod. Time to provide the distraction they'd discussed. _Let's see who catches who off guard._

He leaned over, angling himself to survey the crossword, and pointed at the remaining empty spaces one by one. "One across is 'Aegean'," he said. "Eight down is 'Nabokov', twenty-six across is 'MCM', fourteen down is—move your finger—'phylum', which makes fourteen across 'Port-au-Prince'." He shrugged as the receptionist finally looked up at him with a bemused glare, then pointed at the clue for fourteen across with the best smile he could find. "See, 'Papa Doc's capital idea', that's Port-au-Prince . . . Haiti," he finished with a deliberately awkward glance away.

"Can I help you?" said the receptionist, with a distinct _Please go away_ tone in her voice.

"Yes," said Leonard. He looked back at Sheldon, who nodded meaningfully. The confirmation only made Leonard's desire to throw up stronger, but he hadn't really expected their intelligence to be wrong; it almost never was. "Um, is this the high-IQ sperm bank?"

"If you have to ask, maybe you shouldn't be here," said the receptionist, dryly.

"I think this is the place," said Sheldon quietly, playing his role just a few seconds longer. It seemed to work; the receptionist handed them the usual paperwork and told them to fill it out. His stomach pirouetting like Baryshnikov, Leonard thanked her. "We'll be right back," he added.

"Oh, take your time," the receptionist drawled, deadpan. "I'll just finish my crossword puzzle. Oh, wait." She regarded her paper as if it had just confirmed bad news she already knew. Leonard frowned slightly. This wasn't the typical response. Maybe their intelligence _had_ been wrong. He sat down beside Sheldon and went through the motions of filling out the forms, wishing they'd taken more time to plan this. _We're getting sloppy_ , he told himself with a mix of fear and annoyance.

"Leonard, I don't think we can do this," said Sheldon quietly.

"What, are you kidding? We should be at least semi-pros at this by now," Leonard muttered back. "And you're the one who wanted the extra compensation, so we could get fractional T1 bandwidth in the apartment."

"No," insisted Sheldon. "Look, I do yearn for faster downloads, but that's not the point. Something's wrong about this, and don't pretend you didn't spot it either." He indicated the receptionist with a twitch of his chin. "Passive subjects never react with that complex level of humour, and we didn't come prepared for a quisling scenario."

"Let's not get caught in false dichotomies," said Leonard. Sheldon wasn't wrong, but his problem was that he tended to fall back to escape mode if something didn't match his preparations. "If she had any natural neurological predispositions to DID, the agent might have taken advantage of that. There have been cases like this."

"Oh," said Sheldon. "That's a good point. Let's check. Excuse me?" he called over Leonard's head to the receptionist. "Quick question for you, ma'am: were you sexually abused in any way as a child? Drunk father, sneaky uncle, that kind of thing?"

" _Sheldon!_ " Leonard pulled him back down into the chair and gave a sheepish smile in answer to the receptionist's horrified look. "Sorry, ma'am, my friend's just—he—he's always had a little trouble with personal boundaries," he waffled.

The receptionist's mouth closed, then flattened into a tight and pissed-off glower. "I think it's time for the two of you to leave," she said, voice cracking a little with anger and . . . was that hurt? Leonard thought it might be. Which suggested some very interesting possibilities. _Oh yeah, right_ , he thought immediately after that. _Interesting. That's the right word, uh-huh._

"You're right," he said aloud. "Absolutely. We'll, we'll just go. And get out of your hair. Right now." He gestured Sheldon towards the door and gave a meaningful nod, then backed up, keeping his body between Sheldon and the receptionist's line of sight. "Sorry to disturb you. And about the crossword puzzle. You know, I'm sure you get people coming in here all the time just trying to show off their brains, and really, kinda hard to blame them, they want to make sure you'll accept their genetic material, right?" _Come on, Sheldon, come on, finish setting the damn wards, already . . . ._ "'Cause after all, there's no guarantee any smart person's sperm is going to generate high-IQ offspring, really . . . well, take Sheldon here for a start; he's got a twin sister with the same basic DNA mix who hostesses at Fuddrucker's down in Texas!" In truth, he'd never met Sheldon's sister and had no idea of her IQ, but he told himself he'd apologize for the slander later, if he lived. "What if some poor woman pins her hopes on his sperm and winds up with, I don't know, a toddler who doesn't know if he should use an integral or a differential to solve the area under a curve? I mean, I'm sure she'll still _love_ him, but . . . ."

"Really?" said Sheldon, turning around. He'd adjusted the silver, blue-jewelled ring on his right hand to face outward, and Leonard took the opportunity to do the same with his own ring. "I wouldn't."

"And that's why you handle the physical side of things," said Leonard. " _Now!_ " He ducked down into a squat, arms over his head.

Sheldon jabbed his hand forward, eyes narrowing. The blue jewel on the ring came alight with a searing, blazing blue-white radiance, and a wave of force slammed outward from it, caught the receptionist up and pinned her back against the wall. She gave a shriek that sounded almost more surprised than anything else, her eyes bulging. For a sickening second of dismay Leonard thought, _Oh, crap, we were wrong after all_ —

Then the room abruptly went dark as a nighttime swamp. The temperature plunged. The receptionist's white-coated form vanished into a roiling mass of shadow from which two blazing red lights burned across the air at them. " _Excubitors!_ " blatted a discordant, scouring howl of a voice. The shadow-mass writhed and struggled against Sheldon's binding like a broken-backed snake. " _No! You will—not—have her! Consent! Consent was given!_ "

"Give it up, Smokey the Bandit, we know you're lying!" Leonard shouted back, scrambling to his feet. His breath plumed into the frigid air. He wasn't worried about noise now; Sheldon's wards would keep anything from escaping, at least as long as he was alive. "If you really had consent you wouldn't have needed to hide! We know what you've been doing, and it stops now! Get out! Back to the basement with you!"

" _Noooooo . . . ._ " To Leonard's shock, the shadow-form suddenly wrenched itself away from the wall, bulling its way forward against Sheldon's restraining force like a strong man shouldering his way into a typhoon. Sheldon looked equally aghast. This thing was _way_ stronger than they'd expected. All around the room, lamps, books, clipboards, magazines, file folders and potted plants suddenly sprang into the air and began whirling around them, the wind whipping up into a howling storm. Leonard hunched against it, holding onto his glasses with both hands. Sheldon stumbled backwards until his shoulders hit the wall, but he kept his hand up, the ring still aimed at the shadow-form. The dark thing laughed, and it was like the coughing roar of a lion, deep and hungry but more malicious than any natural beast could ever be.

" _Is this the day, little Guardians?_ " it mocked, still forcing its way towards them step by step. " _The day when you meet the Maker you serve . . . so . . ._ faithfully?!"

"That's certainly a possibility," said Sheldon, and if his voice quivered, it didn't break. Like Leonard, he knew that the less fear you showed, the more blithely you appeared to dismiss any acknowledgement of threat, the angrier—and more foolish—things like this became. "But I really don't think so. Partly because I'm still keeping an open mind on the topic of whether this Maker actually exists, and partly because you've made the same mistake entities of your ilk so often do."

The thing laughed again, still clawing its way towards Sheldon. At the end of its snapping, writhing limbs, night-black, diamond-hard talons formed, gouging the floor as it neared. Leonard had a sudden horrible vision of his intestines decorating those talons. " _What . . . mistake?_ " it hissed.

"Well, it's a perfectly natural one for consciousnesses that normally exist outside a temporal reference frame in a nonphysical medium," said Sheldon. "You tend to forget that once you take over control of a physical body, even in the indirect way you evidently have, you become subject to all the physical factors and conditions of the material universe. Including, in this particular instance . . . inertia."

He snapped his hand closed and yanked hard, reversing the direction of his kinetic pull in a heartbeat, and spun gracefully out of the way as the thing hurtled through the air where he'd stood and smashed hard into the wall. The howling windstorm stopped; every object in the air fell to the floor in a cacophony of clattering crashes and bangs. The swirling darkness faded, thinning out, and for a moment Leonard could see the dazed, appalled face of the woman underneath it. He seized the opportunity, dove on her and grabbed her head with both hands.

" _De profundis clamo ad Te, Domine!_ " he bellowed. He had come to terms with Sheldon's staunch refusal to commit to a theological paradigm—he even understood it to a degree—but he himself had made his choice within months of starting this vocation. " _In nomine Patris, Filis, et Spiritus Sancti, retro me, Satanas!_ " His ring came to searing, blinding life, and he plunged his fist into the darkness surrounding the woman, knotting his grip fast. The noxious, stygian pseudosubstance burned in his hand like acid. "I bid thee, spawn of darkness, get— _out!_ "

He yanked backwards as hard as he could. The swirling, cloudy mass of darkness tore free of the receptionist, solidifying as it did into something that flailed in Leonard's arms like an octopus. Leonard jerked his head at the door to the inner office. "There!" he shouted to Sheldon, who nodded and levelled his hand again in readiness. With all his strength, Leonard spun and heaved the nyctoplasmic mass over the desk to splatter against the door. The instant it hit, Sheldon unleashed a jet of blue-white fire straight into its heart, igniting every strand and thread of the quasi-corporeal body the thing had conjured for itself to hold onto its place in this world.

The thing screamed at a pitch and volume so loud that both Sheldon and Leonard almost fell over. The glass in both outer and inner doors shattered, as did the computer screen, the ceramic coffee mugs and plant pots, and every lightbulb in the room; the water bottle of the drinking station in the corner burst, spewing its contents over the floor, and the coffee table splintered and cracked. And then, with a blinding flash of light and a thunderous _WHAM_ , the thing vanished. Silence crashed onto the room, leaving only a ringing in Leonard's ears. From the way Sheldon grimaced and dug at his own ears, he'd been half-deafened too.

"Ho—lee—crap," gasped the receptionist, still lying on the floor. "What in God's green earth just . . . _happened?_ " She sat up, blinking in bewilderment, looking around. "What the frick is goin' _on_ here?" she demanded.

Leonard indicated the inner door. "You wanna go check on the samples?" Sheldon nodded without complaint—he hated the dealing-with-people aftermath—and opened the door by reaching through the broken window to the knob on the other side. Leonard helped the receptionist to her feet. "Ma'am, there's no easy way to say this, so I'm just gonna lay this on you cold." He took a breath. "You've been the unwitting pawn of a spiritual entity bent on corrupting humanity, which probably obtained access to your subconscious through an induced depression experience based on your childhood trauma—any kind of dissociative potential makes it possible to hide the possession from the subject. My friend and I are basically, well, spiritual exterminators." He tried a smile.

"Oh yeah?" The woman blinked at him, still looking bemused. "So what kinda pay you get in that line of work?"

"Um . . . not a whole lot," Leonard admitted. "Mostly just a stipend. This is more a vocation than a job. But I do have to ask you one more question. Do you want to remember all this?"

"What?"

"If you want," said Leonard, "we can suppress your memories of this incident. We can't do that without your consent, though, or to anything other than what you allow. And it's not even for our own secrecy, 'cause come on, who's going to believe you if you tell them this?" Leonard gestured around at the office. "We just make the offer because we find that an astonishing number of people who go through crap like this, well, they don't _want_ to remember. And I personally never blame them."

"Leonard?" Sheldon called from the inner office. "It's confirmed." He came back in, drying his hands vigorously and looking ill. "A good bunch of the samples back there were tainted. I've destroyed them now, but any child conceived with that sperm would have grown up with the self-discipline and psychic resistance of a gnat. Like an assembly-line of fleshy sports cars, just coasting through a life of vice and crime and poor impulse control until an MEE comes along to drive them off the lot."

"MEE?" said the receptionist.

"Malevolent Extradimensional Entity," explained Leonard, with a sigh. "That's Sheldon's term, he doesn't like the theological implications of the word 'demon'." He nodded at the inner door. "How long's this been going on?"

"Well, by the dates on the vials there were several weeks' worth of samples," said Sheldon. "The MEE probably took her over and tainted them after hours when everybody had gone home, and of course the doctors wouldn't have noticed a thing because it's not operating on the chemical level." He looked at the receptionist. "Excuse me, ma'am, but has anything obtained in the past twenty-three days gone out to clinics for fertilization use?"

The woman shook her head, eyes wide. "Son, you expect me to remember my own name at this point, you're crazy."

Sheldon grimaced. "I was afraid of that. All right, Leonard, you wipe her memory, I'll get the hard drive out of the computer. We'll crack it for the records back at our place." He went to the desk and knelt down under it.

The receptionist held up her hand half-heartedly. "Hey, you can't take that. That's private medical data."

Leonard squared his shoulders and turned to face her, looking straight into her eyes. "Ma'am, you can stick to the law here, or you can let us find and help the poor women who are going to give birth to children genetically twisted from birth to be perfect possession vessels. Like what just happened to you, except it'll be ten times harder to find them and free them without killing them. And to be brutally honest . . . we need your consent to wipe your memory. We _don't_ need it to just pin you against the wall, gag you, and walk out with that hard drive. So what do you say?"

The receptionist stared at him. Then she slumped, walked over, picked up one of the fallen chairs and sat down in it, resting her chin on her hands. "I knew I shoulda finished that crossword at home before coming in," she mumbled. She looked up, and Leonard saw without surprise that for all her deadpan snark, her eyes were wet. "Okay, pal. Go ahead. Do the _Men in Black_ flashy thing. I don't wanna know any more about this. Ever."

Leonard nodded in understanding, and gave her the best sympathetic smile he could. "It's okay," he said softly. "All you'll remember is coming back here after a coffee break and finding the place trashed. And that's all you'll ever need to know."

He put his beringed hand to her forehead, muttering phrases in Latin, then switching to the peculiar language that their teacher had called _Aenochian_ and Sheldon insisted on calling the _ur-Logos_. Cued by the trained triggers of the words, psychic currents sparked to life; the walls between their minds dropped, and he felt his consciousness slide gently into rapport with hers. Her eyes closed. Quickly and quietly, he defined the memories to be buried, envisioning the false scrim of the woman ( _Althea_ , her name came to mind) going downstairs for a coffee and returning to find the devastated room. Atop that, he laid a series of wards that sank into the neurons: it would keep any other entities from finding the weak points into her psyche, at least for a few years. When he was done, he led her over to stand by the door, staring placidly at nothing, waiting for his trigger word to wake back into her normal life.

Sheldon joined Leonard at the door. "If Garner thinks I'm going to personally talk to each and every potential patient on this thing," he said, waving the hard drive at Leonard, "he's gravely mistaken. Just to establish that."

Leonard grimaced. "You could at least call him _Bishop_ Garner, if you don't want to say 'His Grace,'" he said, reaching up to touch each corner of the door, deactivating Sheldon's wards. "I know you won't commit to his explanations, but you could at least be polite. The title's legitimate."

"I'm sorry, Leonard, but I have to be consistent," Sheldon stated. "I'll be polite when I'm talking to him, but if I'm not going to use his terminology, I'm not going to use his title. Besides, you know we're supposed to be discreet about the Church's involvement."

"Figures the only time you'd be any good at keeping a secret is when you want to annoy somebody about it," Leonard grumbled. "Come on. If we hurry we can make it back to the rectory and pick up our stipend checks before three."

"That's right, we could, couldn't we?" Sheldon suddenly smiled and made enthusiastic fists. "Look out, T1, here we come." He looked around. "You know, it's a pity we had to come here on business. You'd think our sperm would be exactly what this place is looking for."

"Oh, come on, like you'd have been able to go through with it," Leonard scoffed. "Do you even know how?"

Sheldon drew himself up stiffly. "Just because I've managed to rise above the crudity of my biological impulses doesn't mean the systems don't _work_ , Leonard. Though I concede," he added, "that you made a good point earlier—we can't really guarantee the result, after all." He looked around quizzically. "I wonder what the protocol is for reneging on a proffer of sperm."

Leonard shrugged. "I think we just leave."

"Fine." Sheldon opened the door. "Let's go. After you, Alphonse."

Leonard bowed. "No, after you, Gaston." As Sheldon nodded and turned out, he turned to Althea and waved at her. "See you," he said, repeating his trigger phrase.

"Bye," said Althea, blinking awake. Leonard carefully closed the door, just in time to hear her startled, indignant cry of "What the _hell_ —?" echo through the broken glass before he hurried back down the hall after Sheldon.

As he caught up to his roommate at the elevators, Sheldon was already on his smartphone, talking animatedly. Without warning, his expression suddenly turned to one of outrage. " _What?_ " he demanded of the phone. "What? No, I told you what it was going to cost! We need more than that! We—oh, Lord's sake, I should have just sold my sperm in the first place! Thanks for nothing, sir!" He hung up and folded his arms, fuming.

"Let me guess," said Leonard. "Bishop Garner just told you how much the stipend actually was, this time around. Or how little."

"Leonard, I swear to you, I do _not_ know why we do this," Sheldon groused.

Leonard raised his eyebrows. "Um, for the salvation and protection of humanity? The awesomeness of wielding power? The chance to delve into the secrets of the universe?"

Sheldon blew out an annoyed breath. "Oh, what good is any of that without some decent bandwidth? They probably have T1 at that church, I'll bet you."

"No, they don't," said Leonard firmly.

"How would you know? You make sure to turn your phone and tablet off whenever you go in."

There was no answer to that, and Leonard decided not to bother looking for one. "By the way," he said instead. "Thanks. For having my back, back there."

"Oh." That did catch Sheldon off guard. "Um. You're welcome. But, you know, we're partners on this, and best friends. I'd kind of think that went without saying."

"Should I not thank you next time?"

"Oh, don't you dare, mister." Sheldon pointed indignantly at him.

Leonard grinned at the floor. They'd survived another encounter, he thought. That was really the most you could ask of any day. If nothing of any interest happened for the rest of today, he'd call that a fair exchange and be grateful.

The elevator signal chimed; the doors slid open, and they stepped inside. Leonard took a deep breath, then blinked as his stomach growled. "Hey," he said to Sheldon. "You wanna get some takeout on the way home?"

"Ah, yes, the great cycle of existence," Sheldon mused. "From the highest practices of the ethical use of transdimensional power, to the basest material concerns." He considered. "I could go for Indian," he said, as the doors closed.

TO BE CONTINUED


	2. Chapter 2

THE DARK MATTER THEORY: THE PARAMETER DEFINITION

By Stephen Tannhauser

 **Description:** Would-be actress Penny discovers her new neighbours Sheldon and Leonard have all sorts of wonderful geeky interests . . . and one very dark secret that will change her life forever.

 **Disclaimer:** The author does not own THE BIG BANG THEORY or any of the characters. Much of the dialogue in this story is adapted from the screenplay for the Pilot Episode, written by Chuck Lorre and Bill Prady.

\- 2 -

Penny hadn't made up her mind yet whether these last few days had been the worst of her life or the best, but with the discovery that the shower in her new unit wasn't working, the balance was definitely tilting towards the negative. A long afternoon of toting boxes and furniture up three flights of stairs had left her feeling distinctly grimy and sweaty, and realizing that she'd left her first and last month's rent cash at Kurt's place hadn't improved her mood. She picked up one of her magazines and fanned herself with it; she'd left both window and door open to get a cross-breeze going, but it wasn't helping much.

She blew out a breath and put the magazine down. Things could be worse, after all. It was a beautiful day, she was young, she was hot, a new phase of her life was starting, she had _finally_ gotten that bastard Kurt behind her, and for all she knew, tomorrow could be the day she was discovered by a movie mogul at the Cheesecake Factory—hell, if they could pick Pamela Anderson off the JumboTron at a Canadian football game, anything was possible, right? A little sweat and grunge was something she could put up with, for that.

Voices from the hall outside caught her attention; she glanced over, raising her eyebrows. The landlord had told her two guys shared the apartment beside hers, which had worried her a moment until he'd reassured her. _Totally harmless,_ he'd said. _Big dweebs, both of 'em; don't do noisy parties, never bring girls back, always pay rent on time._ _Might be a couple, for all I know_ , he'd added thoughtfully.

Well, from the way these guys were gawping at her, it certainly seemed like they might have no idea how to talk to women. They'd definitely never taken any fashion advice from one: the tall, blue-eyed guy was wearing a superhero shirt and plaid pants that should never have left the circus, and the short bespectacled guy was wearing a purple-and-green hoodie that did nothing for his colouring and clashed horribly with the burgundy T-shirt. Shame, really; they were both kinda cute, in an endearing geeky-little-brother sort of way. She smiled. "Oh, hi!"

The awkward volley of exchanged "Hi"s only confirmed the landlord's "dweeb" diagnosis, as did their names when she finally got them. _Leonard and Sheldon, huh?_ Still, it was kind of a nice change from Kurt and his pack to deal with guys who were at least trying to be polite and respectful. And it never hurt to make friends with your neighbours. "Maybe we can have coffee sometime," she finished, and politely shooed them out, closing the door firmly on an equally awkward fusillade of "Goodbye"s. She turned and leaned back against it, blowing out a breath, and smiled despite herself.

Then she looked around at the empty, quiet apartment, at the scattered boxes, the piles of clothes, the off-angled furniture. Nothing moved. Penny's smile faltered and disappeared.

For the first time, it struck her that in her entire life, she hadn't ever lived completely alone. She'd always lived either with her parents, or with Kurt. In the wake of discovering Kurt's infidelity her sheer, infuriated need to just be somewhere, _anywhere_ else had driven her through the entire process of moving out and finding a new place. But it hadn't hit her until now what that meant. Nobody to share coffee with in the kitchen. Nobody to hear moving around the living room or watching TV while she fell asleep. Nobody to come home to.

Nobody to help her turn this place _into_ a home.

She shook her head and took a deep breath. It was okay. This was just—what did shrinks like to say?—this was just another part of the process. And an empty apartment beat an apartment with Kurt in it—or his belly-ringed Goth chippie, come to that. The irritation renewed her energy, and she returned to unpacking, trying hard to keep her mind on positive things. But it was more difficult than she expected, and the knock on the door came almost as a relief.

"Hi. Again," said Leonard, when she opened the door. Sheldon hovered behind him, looking anxious.

"Hi!" She was surprised at herself at how genuinely pleased she was to see the guys again, if nothing else because they were so completely different from Kurt and Kurt's friends—though it turned into amusement when they cycled through another round of "Hi"s. Didn't these guys know how to talk to women at all?

"Anyway, um. We brought home Indian food," said Leonard, holding up a takeout bag. "And, um, I know that moving can be stressful, and I find that when I'm undergoing stress, that good food and company can have a comforting effect. Also, curry is a natural laxative, and I don't have to tell you that, uh, a clean colon is just one less thing to worry about!" He grinned awkwardly, not quite able to meet her eyes.

Penny tilted her head. Had she just been offered a meal, or an enema?

Sheldon leaned down closer to Leonard's ear. "Leonard, I'm no expert here," he muttered, "but I believe in the context of a luncheon invitation you might want to skip the reference to bowel movements."

"Oh, you're inviting me over to eat?" Penny said. "Oh, that's so nice! I'd love to!" Nor was it any kind of a lie; she hadn't eaten much today and only now was her appetite finally coming back. And the thought of company was more welcome than she'd realized, too.

"Great!" said Leonard, smiling back at her. He really was kind of cute, when he forgot to be nervous. She grinned at him, closed her door and headed past them towards the door to their apartment. "So, what do you guys do for fun around here?"

"Well, today we exorcised a malevolent spiritual entity who was using a helpless receptionist to corrupt samples at a sperm bank so the children would grow up more vulnerable to possession," said Sheldon. Penny stopped in the door to 4A, turned and gaped at him. Sheldon paused, then gave a strained grin. "Bazinga."

She looked at Leonard, who was holding one hand over his face. "That's, uh, that's Sheldon's way of saying he's kidding," said Leonard, looking aggravated and embarrassed at once.

"Yes, I'm experimenting with different models of humour," said Sheldon. "That was absurd exaggeration, as you can probably gather." He shrugged, then delivered his punchline in a studiedly casual tone. "All we actually did today was masturbate for money."

Had Penny been less hungry—and truth told, less lonely—that line might well have sent her right back into her apartment behind a locked door. But the blithe unawareness in Sheldon's face that he might have said anything wrong, and Leonard's utterly humiliated cringe, somehow made it all too ridiculously funny to find offputting. She'd wanted to get to know people who wouldn't remind her of Kurt; well, you couldn't ask for better in that line than these guys, now could you?

Inside the apartment, the feeling of having walked into a different world persisted. It was strange, but the place just _felt_ safe; she couldn't have put her finger on why, but it felt more like an honest-to-God _home_ than anyplace she'd lived or visited since coming out here. Like there were strong sturdy walls all around, far thicker than mere plaster and insulation, protecting them all. The neatness and precision of the unit's layout, the sheer volume of all its books, games and entertainment, and the mind-boggling complexity of the equations on the whiteboards were like nothing she'd ever encountered . . . as was Sheldon's explanation for why he didn't like people sitting in his spot on the couch, which she'd done before he'd had a chance to stop her. Fortunately, Leonard had clearly had some practice in compensating for his roommate, and managed to keep the conversation moving, albeit with some clumsiness.

Like, for example, the game they'd just mentioned, which despite herself she just _had_ to ask about. "Klingon Boggle?"

"Yeah, it's like regular Boggle but . . . in Klingon," said Leonard, flushing deeply. Which was more or less what Penny had thought, but she was developing a real appreciation for Leonard's moments of embarrassment; he just looked so cute, like a puppy who wanted to hide in the corner. "That's probably enough about us. Tell us about you!"

Well, that was a more loaded topic than they probably realized. Still, not like it wouldn't have come up eventually. "Um, me, okay, I'm a Sagittarius, which probably tells you way more than you need to know . . . ."

"Yes, it tells us that you participate in the mass cultural delusion about how the Sun's apparent position relative to arbitrarily defined constellations and the time of your birth somehow affects your personality," said Sheldon. "Which is of course ludicrously oversimplified and generalized; the exact assessment of how the inertial-gravitational distribution of mass and energy in local spacetime affects the psychic landscape at the second of a mind's first conscious manifestation can't possibly be boiled down into twelve signs and would require so much astronomical observation and calculation that it wouldn't be worth the effort . . . ." He trailed off, perhaps noticing the way her jaw had dropped.

"How the inertial-gravitational _what?_ " Penny finally said, faintly.

"I think what Sheldon's trying to say is, Sagittarius wouldn't have been our first guess," interposed Leonard, smiling kindly at her.

"Oh. Yeah, a lot of people do think I'm a Water sign," Penny admitted, though from the glares Leonard and Sheldon were shooting each other she was quite sure it wasn't that simple. She decided to try to move past it. "Okay, let's see, what else; oh, I'm a vegetarian, except for fish, and the occasional steak—I _love_ steak . . . ." She told them about her job, about her screenplay, and about coming from Nebraska to be an actress. ". . . and, um, that's about it," she finished, a lot more quickly than she'd expected. "That's the story of Penny."

And oh, Christ, once you left out Kurt, cow-tipping and growing up on the farm, it really was, wasn't it. Was that all there was to her?

"Well, it sounds wonderful," said Leonard encouragingly.

"It was," said Penny. "Until I fell in love with a _jerk_." And completely to her own shock, she burst into tears.

She could feel the aghast silence from Sheldon and Leonard, and couldn't blame them; how would anybody feel if the nice new neighbour you'd invited into your home suddenly broke down out of nowhere? Hiccupping through her sobs, she tried to explain. "Oh, God, you know, four years I lived with him. _Four years!_ That's, like, as long as high school!"

"It took you four years to get through high school?" said Sheldon blankly.

"Don't!" Leonard snapped.

Penny wasn't really listening. "I just—I can't believe I trusted him," she gulped, ignoring their mutters back and forth. "But you want to know the most pathetic part? When it really came down to it, I _knew_ he was cheating on me. I'd seen the signs, I'd heard it from friends, I'd caught him lying about where he was. But somehow, whenever I was with him, it all just . . . went out of my head. Like it stopped mattering and I couldn't even think about it. Is that crazy?"

She'd asked hoping for reassurance, though she had enough of a read on Sheldon now that she half-expected him simply to say _Yes it is_. What she hadn't expected was for both Sheldon and Leonard to sit upright and exchange an alarmed look. It reminded her of the doctors on _House_ , when they heard about the symptom that explained everything, or when the cops on _Law & Order_ recognized a suspect's name. She frowned at them. "What's wrong?"

"Nothing," said Leonard, seeming to come to himself with a start. "No, Penny, look, you're not crazy. It's just, uh, it's a paradox. And paradoxes are part of nature. Think about light. Now if you look at Huygens, light is a wave, as confirmed by the double-slit experiments, but then along comes Albert Einstein and proves that light behaves like particles too . . . ." Now it was his turn to trail off at her expression. "Well, I didn't make it _worse_ ," he muttered at Sheldon.

Penny managed a smile. She sort of thought she got his point, and even if she didn't, his evident concern for somebody he'd only just met was touching. "God, I'm so sorry," she said. "I'm such a mess. And on top of everything else I'm all gross from moving, and my stupid shower doesn't even work . . . ."

"Our shower works," volunteered Leonard. Sheldon snapped to look at him with an aghast gape.

Penny blinked. "Really? Would it be totally weird if I used it?" That got yet another duel of rapid-fire monosyllables, _Yes-No-No?!-No-No_ , but ended with Leonard directing her to the room in question. She smiled in thanks and went to the bathroom, already happily imagining the blessed feel of hot water on her skin.

It was a good thing these guys _were_ such nerds, she thought. Guys like Kurt would have taken a request to use their shower as an invitation for them to join her, more often than not.

* * *

"Well, this is an interesting development," said Sheldon.

"Because you think her boyfriend's Nocturnis?" said Leonard. "Look, I agree it sounds suspicious and I'd like to think that too, but we didn't get any news about anybody showing up on the radar yet, and even if he is, we've got no evidence he's broken the Pax. All we know is that she's . . . ." Leonard paused, trying to think of a diplomatic way to phrase it. ". . . prone to maybe not making the wisest decisions when it comes to bed partners," he finished.

"Well, then, that should be good news as far as you're concerned," Sheldon snarked.

"What?!"

"Oh, please. Did you think your objectives in inviting her over weren't patently transparent, Leonard? For all your protestations of friendship your primary interest is carnal, don't deny it."

"I can and will deny it, and so what if it was?" Leonard challenged, somewhat inconsistently.

Sheldon glared at him in exasperation. "Even if we stipulated that you stood a chance with this woman, which I don't, you're well aware of the risks and practical difficulties of any intimate relationship given our current vocation. That's part of the reason they recruit people like us in the first place, you know that!"

"It's not _unheard_ of," countered Leonard. "And besides, who says I don't stand a chance? I'm a man, she's a woman."

"Yes, but not of the same species."

"Look, I'm not going to engage in hypotheticals here," Leonard growled. "I'm trying to be a good neighbour. That's all." His conscience nagged him enough to make him add, "That's not to say that if a carnal relationship _were_ to develop that I wouldn't participate . . . however briefly."

Sheldon shrugged. "You're the one who converted to a Church which holds non-marital intercourse and contraception to be mortal sins, Leonard. If that doesn't trouble _you_ , I'm not going to bother you further about it."

"Yes, but fortunately I also converted to a Church which includes a sacrament that allows us to get forgiveness for such things." Leonard folded his arms smugly.

"Provided you're sincerely contrite about it," Sheldon countered. "If you do manage to sleep with Penny at some unspecified future date, are you really going to be able to tell your confessor in all sincerity that you're sorry you did it?"

Leonard was spared from answering the question by the door bursting open. Howard and Raj piled in, Howard waving a VHS cassette at them. "Wait 'til you see this!" he declared without preamble.

"It's fantastic. Unbelieveable," Raj agreed.

"See what?" asked Leonard, frowning.

"It's a Stephen Hawking lecture from MIT in 1974," said Howard. "One of the last ever recorded before he became a cr-EEE-PY com-PUUU-terr VOIsse." He grinned at his own imitation of Hawking's vocoder, as he always did.

"That does sound fantastic, but this is not a good time," said Sheldon. "You need to get your Order equipment, and we all need to go."

"What? Where?" said Howard. "Why?" Raj chimed in.

"Because there's a naked woman in our shower," said Sheldon, "and I have profound suspicions about her ex-boyfriend."

Howard grinned. "Yeah, right, naked woman in the shower; your grandmother back in town, Leonard?"

"Gentlemen, I'm serious," said Sheldon flatly. "I have reason to suspect our new neighbour has been dating a Nocturnis of unspecified genus. Once she's finished her ablutions I propose we get her previous address from her and go over to verify whether there is, in fact, any public danger."

"She _lived_ with him for _four years_ , Sheldon," Leonard argued. "If she didn't notice anything or take any harm over all that time, what are the odds there was anything to see?"

Sheldon raised his eyebrows. "So you're staking the safety of our city on _Penny's_ mental acuity and observational skills, Leonard? For that matter, we'll need to make sure _she_ hasn't picked up any critical contagions as soon as we can."

"Wait a minute, wait a minute," Howard interrupted. "There actually _is_ a woman here?"

Sheldon rolled his eyes. "Yes, in the shower. Good grief, Howard, your listening skills need serious work."

"And you want us to take care of her ex so that the way's clear for your own coitus?" Howard pressed.

"I'm not attempting to achieve coitus, Howard!" Leonard snapped.

"So she's _available_ for coitus?"

Sheldon grimaced. "Oh, gentlemen, can we please stop wasting time on the topic of coitus?"

"Wouldn't that be coitus interruptus?" came an amused voice from the hall. They snapped around; Penny lounged against the wall, her arms folded, a towel wrapped around her body. She arched an eyebrow slyly at Leonard. "Nice to know what you guys talk about while I'm out of the room."

Leonard's face burned as if an oven had opened under his chin. "Penny, I—"

"Ah, don't worry about it," said Penny, waving a hand. "At least you waited until I _left_ the room." She jabbed a thumb over her shoulder at the bathroom. "I just wanted to know if there's a trick to getting it to switch from bath to shower, I can't get it to work. Hi, guys." She waved cheerfully at Howard and Raj, clearly enjoying their poleaxed looks. "I'm Penny."

" _Enchanté, mademoiselle_ ," said Howard, the first to recover, as he always was when women were involved. He leant casually on the wall, his silver, blue-gemmed ring flashing in the sunlight from the window. "Howard Wolowitz, CalTech Department of Applied Physics. You may be familiar with some of my work; it's currently orbiting Jupiter's largest moon taking high-resolution digital photographs."

"Cool," said Penny, raising her eyebrows. "I work at the Cheesecake Factory. Sometimes I take photos of birthday parties."

Leonard decided he'd better cut this off before Howard found another way to put his foot in his mouth, or worse, Penny noticed that Howard and Raj wore the same rings he and Sheldon did. "Come on," he said. "I'll show you the trick with the shower."

" _Bon douche!_ " called Howard. "That's French for 'good shower'. I can express the same sentiment in seven languages."

Sheldon looked distinctly aggravated. "One of those had better not be the ur-Logos, Howard."

"What?" Howard scowled. "Just because _you_ don't know how to have fun with your working tools . . . ." The squabbling trailed off as Leonard led Penny back down to the bathroom, trying to ignore her puzzled look back over her shoulder. Maybe Sheldon was right and this had no hope of going anywhere, but it would be nice to at least get a date or two out of it first.

* * *

In the bathroom, Leonard wiggled the switch until he felt it catch; the stream of water switched from faucet to showerhead. "There it goes," he said. "It sticks, I'm sorry, I—" He turned just in time to see the towel fall and the barest flicker of Penny's body before she disappeared behind the shower. "Oh! You're just going to step right—okay, I'll, um . . . ." He trailed off, then got up and headed for the door.

"Hey, Leonard?" Penny called, just as he put his hand on the doorknob.

The reflex habits of lifetime insecurity betrayed him. "Penny, I'm so sorry about the whole 'coitus' thing out there," he found himself babbling, "that's really just Howard, I hope you realize I'd never—you know, I wouldn't do anything, well, untoward, and I, uh, I . . . ."

"Leonard." Penny stuck her head around the shower curtain, sodden hair framing her face. She grinned. "It's okay. Really. I actually just wanted to ask you a favour."

"A _favour_." Leonard slumped in relief. Well, he hadn't blown it so far. "A favour, sure, you can ask me a favour; I'd do a favour for you."

"It's okay if you say no," Penny assured him earnestly.

"Oh, I'll probably say yes." To his own surprise, Leonard found himself returning her grin, his look half rueful, half amused.

Penny's eyebrows shot up; then her own grin broadened. "I'm only saying because it's not the sort of thing you normally ask a guy you just met . . . ." Her eyelids lowered, and she gave her head a slight coquettish tilt. The look touched off a startling warmth in Leonard's gut. He felt dazed. Was this actual, successful _flirting_ they were doing here? Was this that so-called "chemistry" he'd heard so much about and never understood? Images of loofahs, soap, and slippery curves filled his head.

"Well," he said, doing his best to look cool and casual, "I'm not the normal sort of guy." Thankfully, he just barely kept his voice from cracking. "So please. Ask whatever you'd like."

"Good." Penny's grin changed to something slightly sheepish; she dropped her eyes and ran one fingertip along the edge of the shower curtain. "Well, I was kinda hoping . . . that you'd, well . . . that you'd like to join me . . . ." Leonard's breath stopped. ". . . when I go back to my old place to get some money from my ex."

A mental record needle scraped an earsplitting screech across Leonard's brain. At last he found his voice. "You, uh . . . what?"

"You _and_ the guys," Penny clarified. To her credit, she at least had the grace to look a little embarrassed. "Just for some backup, so he can't be his normal dickish self about it if he wants to. And some moral backup for me, too, in case he decides to be charming and I get tempted to forgive him again." She looked up through her eyelashes again. "Please?"

Leonard closed his eyes and sighed. _I'm a defender of humanity against the forces of supernatural evil, God,_ he thought, aiming the remark skywards. _If that isn't going to get me out of the "friend zone," what is?_

There was no answer. There never was, for prayers like that.

TO BE CONTINUED


	3. Chapter 3

THE DARK MATTER THEORY: THE PARAMETER DEFINITION

By Stephen Tannhauser

 **Description:** Would-be actress Penny discovers her new neighbours Sheldon and Leonard have all sorts of wonderful geeky interests . . . and one very dark secret that will change her life forever.

 **Disclaimer:** The author does not own THE BIG BANG THEORY or any of the characters. Much of the dialogue in this story is adapted from the screenplay for the Pilot Episode, written by Chuck Lorre and Bill Prady.

\- 3 -

"I really think we should examine the chain of causality here," said Howard. Leonard had to give him props; there wasn't much that could get Howard Wolowitz to ignore being crammed into the same backseat with a girl as beautiful as Penny, but going into a possible Nocturnis confrontation blind was always one of them. He didn't lack for guts, but like Sheldon, he preferred knowing what he was up against, and he was prone to kvetching when nervous or irritated.

"Must we?" said Sheldon impatiently. Leonard would have agreed, but he was concentrating on the road.

"Event A," said Howard. "We're asked to help our new neighbour retrieve some cash from the home of her ex. Now this in itself I don't mind," he said sidelong to Penny with a gallant nod of his head, "I'm always happy to render assistance to a cheesecake-scented goddess." That earned him a smile, albeit a slightly strained one. Then he turned back to glare at Leonard and Sheldon in the front seat. "However, Event B is: We decide to do so immediately, without, oh, I don't know, picking a time when he's likely to not _be_ in this home, which would minimize the likelihood of a face-to-face confrontation involving damage _to_ most of said faces. Query: On what plane of existence is there even a semi-rational link between these events?"

"Guys, come on," said Penny patiently. "There's not going to be a confrontation, I'm not expecting any of you to _fight_ Kurt . . . I mean, look, I'm sorry to be blunt but he'd probably wipe the walls with you. I just want backup for when I lay it on the line to him."

Howard narrowed his eyes at her. "Backup, and-slash-or legal witnesses?"

"Howard, can it," said Leonard, as firmly as he could. "You know how it is when a relationship breaks up. We all do."

"Actually, given that none of Howard's sexual partners that we know of have lasted longer than two or at most three encounters, I'd suggest he doesn't," Sheldon corrected. "And I think it's a safe estimate that nobody else in this car does either."

"What?!" Leonard sputtered, aware of Penny's curious look from the back seat. Great—the last thing he needed her thinking was that he was a completely inexperienced dweeb. "I, uh, I broke up with Joyce Kim!"

"No, she defected to North Korea to escape arrest for espionage," said Sheldon. "My own history, of course, is one of unblemished asceticism, and while I don't know the details of Raj's youth, his selective mutism speaks highly against any success in that area, so my point stands: None of us know anything about breakups."

"Selective mutism?" Penny frowned, and turned to Raj, who was wedged into the back seat on her other side. "Raj, what are they talking about?" Raj froze, eyes like saucers, and managed a feeble grin. Penny's frown deepened. "I'm sorry, um, do you speak English?"

"Oh, he speaks English," said Leonard. "He just can't talk to women. He's selectively mute around women; hence, selective mutism."

"Really? Why?"

"He's kind of a nerd," said Howard, his tone clearly saying without words, _Duh_. Raj gave him a sour look.

"Wow." Penny's mouth twitched in a smirk, half amused, half sympathetic. She patted Raj's cheek kindly. "Well, don't worry about it, sweetie. Lots of girls like a man who knows when to shut up and listen." She leaned over and kissed the cheek she'd patted. Howard's eyebrows shot up. Leonard only barely kept his jaw from dropping in dismay. Raj shifted in the seat and, the moment Penny turned away from him, broke out in an incredibly wide grin that made Leonard want to punch him.

Sheldon, as was typical of him, had noticed none of it. "Penny, I'd like to ask you something in return for our assistance here."

"Sure, name it."

"If, when you are speaking with Kurt, you begin to experience a powerful desire to resume your status as one of his intimates in contravention of your own good sense and judgement, notify us immediately."

Penny blinked. "I'm sorry, what?"

"Tell us if you start feeling like you want to get back together with him," Leonard translated in a wry deadpan. "Especially if it's really turning your head around."

"That's not a bad idea, actually," said Penny thoughtfully. "But I don't want to say anything like that where Kurt can hear it. His head's swelled enough already." Then she brightened. "Oh, I know; let's do a code word, like a safe word. Um, what's a good word that you'll all recognize right away as the 'get me out of here, I'm losing my resolve' signal? Something unusual enough to stand out."

"'Antidisestablishmentarianism'?" suggested Sheldon. "Which interestingly enough, Penny, is the longest word in the English language at thirty-two letters."

Penny stared at him. Leonard sighed. "Sheldon, it might be an idea to think of a word Penny can work into an ordinary conversation easily."

"It might be an idea to think of a word Penny can _pronounce_ ," said Penny. "Okay, um, how about this? If I ever say the full word 'television' instead of just 'TV', that means I want you to get me out of there before I make a dumb choice."

Sheldon snorted. "There you go, Leonard. And you thought your current vocation was a demanding one."

Penny frowned, though she looked more confused than anything else. Leonard decided to move the conversation on before she understood Sheldon's insult. "Tell me, Penny, when you did break up with Kurt and leave, exactly what were the circumstances?"

Penny flushed. "Look, Leonard, I'd really rather not talk about that . . . ."

"If it was personally humiliating, we certainly understand your reluctance," said Sheldon, turning to look over his shoulder. "But Leonard has a point. Not only will sharing the experience help you get over it more quickly, it will give us useful information for any reminders about why you chose to leave him."

Penny bit her lip, then sighed. "Yeah, I guess that's a good point. Well, it's probably nothing you haven't heard before, but—I came home after getting the job at the Cheesecake Factory, 'cause the interview ended early and I wanted to surprise Kurt with the good news that I could help cover the rent again. Well, I was the one who got the surprise; I find him boffing some Goth chick with a belly ring and a dozen tattoos all over the place—"

"Um, where exactly were these tattoos?" interrupted Howard, a lubricious gleam in his eye. "Do you remember what they looked like? Just to help me, you know, visualize . . . ."

"Howard!" Leonard snapped.

Penny gave Howard the stink-eye for a moment, then resumed her story with a sigh. "Anyway, I just absolutely lost it. I grabbed my baseball bat, broke his clock-radio, his lamp, that stupid MMA belt he always kept on our wall—"

"MMA?" said Howard, his tone now completely different from his last interruption. "As in . . . 'mixed martial arts'? This . . . wasn't a workout belt or something, was it? Or a souvenir?"

"Nah, it was a victory trophy of some kind, regional I think. I don't know. Kurt's always been into that stuff." Penny shrugged indifferently, not noticing the way both Raj and Howard were now looking distinctly sick. Even Sheldon seemed disturbed. "So I screamed and waved the bat at Goth-chickie until she cleared out of there—" She gave a distinctly gleeful snicker. "Didn't even have time to put her panties on, the bitch—and then I grabbed my basics and left. That was two days ago; I went back this morning when I knew he'd be working and cleared the rest of my stuff out. I just forgot the cash envelope because I'd stuffed it in my yoga pants drawer so he wouldn't find it." She slumped back in the seat and put her hand over her face. "God, that still makes me feel so stupid. I should have known. I mean I really should have known."

Sheldon nodded. "Anger born of personally witnessed betrayal," he said to Leonard in an undertone. "That is one of the more effective counters for low-grade psychic influence."

"And for perfectly normal bad relationships," countered Leonard, at a similar _sotto voce_ level. "But I see your point." He raised his voice. "Penny, you said Kurt was working in the morning—does that mean he was, er, out and about in the daylight? Or does he work indoors?"

Penny frowned. "What difference does that make?"

Leonard thought fast. "Just . . . if he normally works nights, he'll probably be extra tired and cranky in the afternoon, if we have to wake him up. Just trying to get a read on how this is going to go."

"Oh. No, I don't think you have to worry about that—Kurt's one of those people who doesn't need a lot of sleep; I've seen him perfectly happy on, like, four hours a night for weeks at a time. I mean, he's got a pretty short temper, but I've never seen him cranky just 'cause he was tired. He does shifts as a bouncer at night and some part-time landscaping work in the day, so he keeps pretty busy."

Sheldon gave Leonard a meaningful look. Leonard bit his lip. Full ability to tolerate sunlight meant they weren't dealing with a vampire, at least, though he had never really believed that was a possibility; humans who became long-term lovers for the _ybir_ seldom survived one year, let alone four. Excessive stamina, energy and physical prowess, and sex appeal sufficient to drive partners to foolish decisions . . . well, that _could_ indicate one of the easily-passing Nightfolk, like a Fae changeling, or given the short temper more likely a breed of _dwerghr_. But it could also just indicate one of those really annoying people who got a lucky draw in their genetic poker hand and took all the advantage of it they could.

Leonard fought back a sudden wave of morose annoyance. Sheldon was right; he had no business getting depressed that a woman like Penny might have tastes in men he couldn't possibly meet, especially when he shouldn't be pursuing her anyway. And it was not only the height of selfishness but the height of wishful thinking to wistfully hope Kurt might actually be a Pax-breaking Nightfolk. Bystanders were endangered whenever the Excubitors had to act at all, and tended to get hurt whenever they acted too hastily: that was one of the reason they were generally much more cautious and careful. This was exactly the sort of situation they really should have reported to Bishop Garner first, so that at the very least if all four of them vanished, someone from the Order would know to follow up.

Penny looked around at them. She might not have the eidetic intellect of any of the guys, but it was clear she was far more keenly attuned to atmosphere than they were, and had quite aptly read the sudden silence in the car as evidence of worry or fear. "Hey, guys," she said, "I just want to tell you all, I'm really grateful for your help on this. I owe you all, big time, and once I get my money I'll take you all out to dinner if you like. Trust me. This is really not going to be a problem."

"In other news, Chamberlain promises peace in our time," muttered Howard.

Penny frowned. "What?"

"Nothing, nothing," Howard sighed. Leonard contemplated punching him when they got out of the car, then decided not to bother. _Howard's gotta Howard_ , he thought.

* * *

Penny's blithe serenity took a visible hit when she discovered, after several fruitless attempts on the security pad beside the main door, that her entry code to the building wasn't working any more. "Son of a _bitch!_ " she snarled. "That steroid-drenched _bastard!_ He's already cancelled my code!" She jabbed the buzzer for unit #406 hard, holding it down for several long, sustained bursts. Howard jabbed Leonard hard in the side and mouthed, _Steroid-drenched?_ with panic in his eyes. Raj didn't look much happier.

Finally a deep voice crackled back from the speaker grille, its tone a mix of sleepiness and annoyance. " _This better be freakin' important. Who is this?_ "

"It's Penny, Kurt!" Penny shouted into the pickup. "I'm here with some friends to pick up the last of my stuff, you better let us up or we'll—we'll . . . ." She trailed off, evidently stuck on what would make both a plausible and effective threat.

" _Or you'll what, exactly?_ " Kurt sounded amused now. " _Look, I'll cut you slack for being mad. I was a jerk. I admit it. But don't go making threats you can't do anything about, 'kay, babe?_ "

"Babe?!" Penny repeated aloud in visible disbelief.

Leonard lifted a hand. "Penny—maybe I should try. We wanted to keep this civil, right?" Fuming, Penny ceded her place in front of the speaker grille, and Leonard leant in. "Uh, hello, sir, um, Kurt? My name's Leonard, I'm a friend of Penny's, she really just wants to pick up her stuff. If you could let us all in, that'd be great."

" _Get lost, creep._ " Kurt's voice was much less amused now. " _If Penny wants to see me she can come up by herself. The rest of you, screw off._ " The speaker fell silent.

Penny's mouth tightened. "Okay," she said to Leonard and Sheldon. "Okay, I'm going to get him to buzz me in, and I'll promise it'll be just me coming up. Then you sneak in behind me and—" She stopped at the uneasy looks the guys traded, then clenched her fists and rolled her eyes skyward with a groan. "Oh, my _God_ , what the hell's wrong now?!"

"Entering the building under false pretenses is a serious problem, Penny," said Sheldon. "If the situation is what I think it is, it may actually be a prohibitive one."

She stared at him. "Why?! Are you seriously worried about me breaking a promise to this asshole? This used to be _my_ flipping _apartment!_ "

"We understand, really," Leonard cut in, thinking frantically. They needed an explanation Penny would believe; telling her that the negative psychic feedback of breaking their word, even given second hand, could fatally weaken their thaumaturgical _oomph_ at the wrong moment would only have her calling the nearest mental hospital. "But the keywords there are 'used to be,' unfortunately. That means if we enter the building after fraudulently obtaining permission, we're trespassing, and he'll have every right to call the police on us. Hell, he might even beat us up and get away with it as self-defense."

Penny blew out an aggravated breath and stepped back, gesturing at the door. "Okay, genius, it's so important not to break a promise to the guy, _you_ get in there."

Leonard stared at the door, then at Penny, then at his friends. "All right then; we will," he said, squaring his shoulders. He turned to the guys and rubbed his hands. "Okay, guys, we can do this, right? I mean, we've got a combined IQ between us of close to 700—we should be able to figure out a way to get past a stupid door."

"I could try to pick the lock," volunteered Howard. He bowed to Penny with a smile that, Leonard thought, _probably_ wasn't meant to be as leerish as it came off. "Tell me, milady, might you happen to have a bobby pin in your hair?"

Penny frowned. "Well, I'm not a twelve-year-old girl, so, no."

"Ah." Howard held his smile a beat longer, then collapsed. "Well, I'm out. Leonard?"

Leonard pursed his lips. Tentatively, he felt the door's handle, tested its weight, and pulled gently. It didn't move. He grabbed the handle with both hands and shook vigorously. The door rattled in its frame but stayed put.

"It's just a privilege to watch your mind at work, Leonard," said Sheldon sourly.

Penny threw up her hands. "Okay, you know what? Forget it. I'll come back later by myself, get this settled, one way or another . . . ."

"No, no, Penny, don't do that!" Leonard pleaded. "Come on, don't give up. If I'd given up at the first little hitch I would never have been able to identify the fingerprints of string theory in the aftermath of the Big Bang."

"Okay, okay, fine," Penny sighed. "I'm sorry. You're right. What should we do?"

"Um . . . ." Leonard met Penny's expectant, hopeful eyes and stopped, mind suddenly blank. _Oh, crap,_ he thought despairingly. This was no way to impress a girl.

Whether it was Fortune or God which smiled on him then, Leonard didn't know, but he decided to toss a few prayers skyward in thanks anyway. As he havered helplessly, two Girl Scouts, their arms full of cookie boxes, strode sunnily up to the door and, without missing a beat or speaking a word, solved the problem by dint of swiping their hands down every button on the intercom panel in one go. Within seconds the buzzer went off. The girls grabbed the door, pulled it open and went smugly in.

Raj and Howard stared, jaws hanging. Sheldon cast a glare at Leonard. "What do you think _their_ collective IQ is?" he grumbled.

"Get the door, get the door, _get the door!_ " yelled Penny, though she rendered the admonition somewhat moot by diving forward and grabbing it herself before any of the guys could move. She paused in the doorway, holding it open, blew out a relieved breath, then looked at the guys and jerked her head inwards. "Well, you coming?"

* * *

Penny led the way striding down the fourth-floor main corridor towards the apartment, which was why she didn't see the guys behind her suddenly slowing and exchanging worried looks as they neared unit #406. Nobody needed to speak aloud to recognize that they all felt something coming off that unit—an aura of heat and hunger, a sweltering taint in the air that left a musky psychic stench in their nostrils. Raj mouthed something at all of them, his eyes wide and white in his face: it took Leonard a second to work it out. When he did, his stomach suddenly clenched and dropped through the floor. _Dwerghr_ , Raj had said.

Leonard nodded, lifted his hand so the others could see it and deliberately turned his ring outwards. The others did the same as Penny lifted her hand and pounded on the door. " _Kurt!_ " she shouted. "Kurt, it's me! Open up! Now!"

The psychic stench intensified. Noise came from the other side of the door: footsteps, approaching. Leonard swallowed, feeling his skin tingle. A second later, the door opened.

The man who stood there, arms folded, was one of the largest people Leonard had ever seen in his life. He stood well over six feet tall, and his shaved head shone slightly in the light of the unit's hallway; his biceps were bigger than Leonard's thighs, and his T-shirt strained over a barrel chest. In and of itself none of that would have frightened Leonard now as much as it once might have—the Excubitors forbade using thaumaturgy on ordinary people but allowed for the possibility of self-defense—but it was the aura boiling off him, more than anything else, that was spiking ice through Leonard's veins. This man was Nocturnis without a doubt, and Leonard thought Raj was likely right about his kind. Even Penny took a step back, as if only just now realizing how intimidating her ex actually was.

"Wow," said the guy in a deep voice, looking amused. "You felt you had to bring a whole posse to back you up, Penny? Come on. You know I'd never hurt you." His voice dropped, becoming warm and rich. "Why don't you come in, have a beer, send the Geek Squad here home. We'll talk things over. Let me see if I can make things up to you." He held out his hand. On it was a heavy gold ring, a bright green stone glinting sharply upon it. Penny stared at Kurt's hand, then looked up at his dark eyes and swallowed.

Leonard wasn't sure he'd ever experienced such a conflicted reaction. On the one hand, the sight of that ring evaporated ninety percent of his fear. On the other hand, it was a gut punch of disappointment. That ring meant Kurt had sworn the oath of the _Pax Tenebrum_ , the Peace of Shadows: he had bound himself never to harm a mortal, reveal his nature or exercise his Nightborn powers upon someone without the mortal's permission. Which meant that until he actually broke the binding by doing any of that—something that would turn the ring into a danger-alert beacon that every Excubitor in the Greater Los Angeles basin would sense and descend upon—none of them had any grounds to touch him. At all.

Leonard's mouth tightened. Kurt obviously wasn't using anything to influence Penny beyond the basic raw sex appeal of many Nightfolk; the long-lost Excubitors who had drafted the Pax had reluctantly had to allow that specific exclusion, as that kind of low-grade magnetism wasn't something that could be easily turned off and was only marginally supernatural in its effect, meaning that it was in principle resistible by mortal humans with sufficient resolve. But that didn't mean she couldn't use a little purely mundane help. Penny's hand had just begun to lift, probably to take Kurt's, when Leonard prodded her sharply in the arm. She started, then rounded on him with a glare. He held up his hands placatingly and murmured, "Um—Penny? Television."

Penny blinked, then took a deep breath; some of the colour faded from her cheeks. "Right," she said. "Right." She turned back to face Kurt and deliberately stuck her hands in her armpits, her green eyes flashing. "Thanks for the offer, Kurt, and I will come in, but my friends here are coming in with me. I just need to pick something up and then I'm gone. For good."

Kurt shrugged, not appearing fazed. "Whatever, babe. The more the merrier." He stepped back and gestured them in. Penny strode past him without looking. Kurt only smiled, and Leonard didn't like that expression at all. He liked it even less when Kurt turned back, and the glint in his eye told Leonard—without any psychic attunement needed at all—that he knew exactly who they were and why they were here.

His words only confirmed it. "So, you guys're the local Pax heavies? Man. You're a lot less impressive than the guys my sponsor told me about."

"You know, I find it offensive that you use the same term for the creature who made you a monster as AA members use for the people helping them fight their addictions," said Sheldon stiffly. "Whatever happened to the classical terminology of the Old World?"

"Move with the times, dude," said Kurt. "And you know you're not supposed to use the M-word these days, right? I mean, _we_ can to each other, if we want. But that's hate speech coming from you."

Howard stiffened and drew himself up. "You know, I don't think you get to talk about hate speech to _me_ , buddy." Leonard felt a surge of admiration for his friend; for all Howard's kvetching and discomfort about confrontation, when he got genuinely mad, he didn't let much stand in his way. "You think having to wear that ring's bad? Try wearing a Star of David sewn on your clothes."

"Oh, gimme a break," Kurt snorted. "Like I care about what humans do to each other any more. Cut the crap, guys. You're here for an official Castigation, gimme the papers. You're not, you can shove off." His eyes moved to Leonard, and locked; his nostrils flared. "Unless you're here for something else . . . ." He took a deeper breath, and smiled in sudden understanding, as if something in Leonard's very scent had given him away. "Oh, shit. You want to get in her pants, don't you?"

Leonard couldn't help himself; he flushed, his face painfully hot. Kurt laughed, then lowered his voice and leant down, putting his face almost right into Leonard's. "You're just _praying_ for me to give you an excuse to blow me through the wall, so you can be the white knight. Well, you can go on dreaming, buddy." Kurt poked Leonard hard in the chest. "You can't touch me. You can't touch _her_. She's _mine_. And don't you forget it."

"Kurt?" Penny stood in the hallway behind him, a thick white envelope clutched in her hand. Her face was almost as red as Leonard's, but for an entirely different reason. "If you want to act like a jerk to my friends, I can't stop you. But don't you _ever_ tell somebody I'm _yours_ again."

Kurt sighed theatrically, straightened, and turned, smiling. "You're right, babe, I'm sorry, I should have—" He stopped. His eyes narrowed, and he pointed to the envelope. "What's that?" His voice had gone flat and quiet. For the first time since the door had opened, Leonard's skin suddenly tingled with cold.

"It's _mine_ , is what it is," Penny shot back.

Kurt snorted. "I don't think so." With startling speed he took two steps forward and ripped the envelope out of Penny's hand, flipped it open and thumbed through the stack of cash inside. His voice went even flatter. "You took this out of my private cash box, didn't you?"

"I didn't take a cent more than I was due, Kurt," Penny snapped. "That's every parking ticket I ever paid for you. That's the five hundred bucks I had to spend to bail you out that time you pissed on the cop's car and told him you were 'marking your territory'." She made air quotes with her fingers, not noticing the looks Leonard, Sheldon, Raj and Howard shot one another: Kurt's claim might have been far more literal than Penny realized. "That's the gas money you kept promising to pay me back and never did. That's the shoes I had to sell to help pay the phone bill when you lost your bouncer's job after breaking a teenage girl's nose—oh yeah, I found out about that! And that's four hundred bucks out of the seven hundred you told me you needed to fix your muffler, because I talked to the mechanic and found out you only needed three hundred for the muffler and the rest went to upgrade the stereo system!" She jabbed a forefinger back into the apartment. "If you go look at the fridge door, you'll see I left you a god-damned itemized _expense report_ for every dollar in that envelope, though who knows when you'd ever have seen it because God knows you never paid attention to the bills I put up there!" Penny stuck her hand out, palm up. "Every cent in there is _mine_ , Kurt. You always brag about how you always pay your debts, right? Well, prove it."

Kurt's shoulders tensed, hardening like rocks. The air around him boiled, seeming to flare with an acid heat. Leonard gulped and knotted his fists, flooding the blue gemstone of his ring with psychic power; behind and around him, he could feel Raj, Sheldon and Howard doing the same. But the sudden surge of energy caught Kurt's eldritch senses, as keen as their own, and he glanced over his shoulder at them. The air sang for a long, long second with silent tension.

And then Kurt took a slow, deep breath, and relaxed. The red heat surrounding him washed away. "You know something, babe," he said. "You're right. You're absolutely right."

"I am?" Penny blinked.

"You are. You're owed that money." But as Kurt talked, his voice dropping back down into that rich, deep warmth, he looked back over his shoulder—and did something that pierced Leonard's gut with cold. With deliberate visibility, he took the ring off. "'Cause after all, here in _my own home_ ," he emphasized the words, "it's nobody's business but yours and mine how we settle our debts. Right?"

 _Oh, shit._ It was another of the Pax's necessary loopholes: the one place where a Pax-sworn Nightfolk could freely remove his binding ring was his own private demesne, and like police officers who needed probable cause, no Excubitor could enter or scry into a Pax-protected dwelling without permission unless they had grounds to suspect the inhabitant was actively, presently abusing a mortal within—grounds Kurt would no doubt make very sure to deny them, as long as they were still here. Leonard looked imploringly at Sheldon, but the taller man only shook his head unhappily.

Leonard's stomach sank. If Sheldon's rule-loving eidetic memory couldn't recall any grounds for taking action, then there almost certainly weren't any. His fingernails bit into his palms, not from calling power this time but purely from sheer frustration. The _one time_ it would actually have been _good_ for Sheldon to bring up a frustrating technicality . . . .

"Um—right. Okay." Penny still looked thrown. "So . . . can we go, then?"

"'We'?" Kurt made a scoffing sound and waved at Leonard over his shoulder, without turning around. "They can go, I don't care. But c'mon, Penny. Why don't you stick around, have that beer? For old times' sake . . . ." As if Leonard and the guys weren't even there, he moved down the entry hall towards Penny, sliding his arms with fluid grace around her waist before Penny even seemed to realize he'd moved. "I think we can still work this out. Come on." His voice took on an even huskier note, so sly, sensuous and decadent Leonard half felt his own body twitch in response to it. "You remember how good it was for us, when it was good, right? Do you really want to give that up?"

Penny stared up at him, eyes wide, lips parted, cheeks flushed. Yet even now, the arcane senses Leonard had acquired with his initiation to the Excubitors betrayed the reality of it: Kurt's power had still not broken the bounds of what was permissible under the Pax, and he was in his home, with a mortal who had chosen to be there. Sheldon's painful grip on his shoulder, and the fierce glare he sent Leonard, only drove the point home. There was absolutely nothing Leonard could do to Kurt that would change a thing here . . . .

. . . but there _was_ one other person that deserved to know the truth of what that was.

Without letting himself think about what this meant, or the price he and anybody else would have to pay, Leonard twisted his ring so the stone was on the inside of his fingers. He drew a single deep breath, pulling all his anger and indignation into his fist like deuterium plasma collapsing towards a fusion flash-point. Then he held up his hand, palm out, and opened his fist. The power vibrated in his ring with leashed fury, glowing like a star pinned to his palm. Sheldon jumped back in sheer reflex, and Raj clapped his hands to his mouth; Howard stared, mouth open.

"Penny?" It wasn't a shout, but it was loud enough to cut through the tension between Kurt and Penny like a whipcrack; Kurt spun, face distorting into a snarl, and Penny shook her head and blinked at Leonard as if she'd forgotten he was there. But before she or Kurt could say anything, Leonard said the magic word—and like all the best enchantment-breaking words, it was a word that only the captive princess and the wizard really understood.

"Television."

TO BE CONTINUED


End file.
